[Freeciv-Dev] Re: (PR#10125) Pollu_Prod_Pct

["Vasco Alexandre da Silva Costa" <vasc@xxxxxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=10125 >

On Wed, 15 Sep 2004, Jason Short wrote:

>
> <URL: http://rt.freeciv.org/Ticket/Display.html?id=10125 >
>
> Per I. Mathisen wrote:
>
> > I still do not understand
> >   1) why its name contains PCT (percent) even though it does not use
> > a percentage value
>
> Obviously an error.
>
> >   2) why this strange way of calculating pollution is used
> >
> > Could it not be easier solved by using a percentage value? Pollution is
> > reduced by the given percentage value. For recycling center, pollution is
> > increased by 66% but reduced by 50% if you have a nuclear plant or a hydro
> > plant. This is possible using existing effects:
> >
> > effect         =
> >     { "name", "range", "value", "req_type", "req"
> >       "Pollud_Prod_Pct", "Player", 66
> >       "Pollud_Prod_Pct", "Player", -50, "Nuclear Plant"
> >       "Pollud_Prod_Pct", "Player", -50, "Hydro Plant"
> >     }
>
> You're talking about two different things here:
>
> 1.  Removing the janitors group.  Vasco and I talked about the necessity
> of having groups.  It is possible to do it without them but takes
> exponentially more effects (and thus, exponentially more time to iterate
> over the effects).  In the above case things look okay for recycling
> plant, but what are your effects for nuclear plant, hydro plant, and
> hoover dam?  What happens if you have both nuclear plant, hoover dam,
> and recycling center at the same time?  It's just not worth the effort
> to figure this out when groups solve it already.
>
> (Replacing a group of size n with effects directly requires 2^n
> additional effects.  This may be simplified in the above cases since
> some buildings may not be able to exist at the same time.)
>
> 2.  Replacing the multiplier by a percentage.
>
> The problem with this is that negative percentages do very poorly when
> added.  In the current ruleset this isn't a problem because no two such
> effects can ever be active at the same time.  But imagine if you had two
> -66% effects active at the same time.  What should the result be?

If you only had those effects, negative. But that does not matter. We
could just trust the ruleset writer on this.

> If the issue is that you want a nice round divisible-by-100 number then
> we can make these values into percentages.  The value "3" becomes 300%
> and the value 2 becomes 200%.  But we still need to do it by dividing,
> not adding.

This is not much different from how something like the Science Bonus
works. Except it divides instead of multiplying. Yes there will be some
minor errors because /3 != *100/33, but I think we can blissfully ignore
them.

> This is ugly and it prevents having effects that increase pollution.
> But until we allow effects to be applied in series rather than in
> parallel, I don't see a way around it.

---
Vasco Alexandre da Silva Costa @ Instituto Superior Tecnico, Lisboa